The global electrical consumption hit 19,090 billion kWh in 2012. That number is bound to increase in the coming years due to population growth and rapid industrialization of growing economies.
On average, the earth receives 164 Watts of solar energy per square meter. This works out to 84 billion kWh of potential electrical generation per day. The problem isn’t whether if we receive enough solar energy. The issues with solar relate to effectively capturing the energy and storing it.
Nadine May (Technical University of Braunschweig) wrote a thesis called “Eco-balance of a Solar Electricity Transmission from North Africa to Europe”, and calculated that a small area in North Africa could supply the world with all of it’s electrical power through solar energy (see figure below).
The smallest red box (45km x 45km) represents the area needed to power Germany, the second largest box represents the area needed to power the European Union (110 km x 110 km), and the largest box (254 km x 254 km) represents the area needed to power the globe.
Again, the biggest issues with solar energy don’t relate to generation, but rather transmission and storage. Most of our power grids are alternating current, and solar panels produce direct current. This means that the direct current has to be converted to alternating current using an inverter before it can be fed to the grid. This can pose problems for the electrical grid as many inverters do not produce high quality alternating current – which destabilizes the grid. Power storage is also a big issue, but companies such as Tesla are beginning to tackle the problem by producing scalable and affordable battery storage options.